When we spread our digits we see a very small patch of skin between our digits.The same feature is very well seen in bats.flying squirrels and flying lemurs,etc.Does this not show that humans ancestors might have evolved from tree dwelling organisms.

If that patch of skin wasn't there between our "Digits" then we wouldn't be able to open our fingers too well because that patch of skin allows you to spread your fingers easily. And, it also allows us to swim better with our hands as "Oars".

As I know only bats have skin between their phalanges. Others such as squirrels just have between front and hind legs. And no it does not show that we evolved from any of those groups. Neither from aquatic forms like Lutra (otter I think) or beaver although thay also have swiming skin between their phalanges.

It must be a coincidence, as bats evolved to fly, not glide. I've never seen a morphology of skin between the digits that would allow for gliding rather than flight, and no human forerunner could fly. It's much more reasonable to think along beetle's and zim's lines.

That cannot be true the ancestors of monkeys might be tree dwelling animals like the ancestors of bats.the flying squirrel example was to tell that tree dwelling mammals evolved to flying squirrels,bats,small monkeys,etc.

"Nothing in biology makes sense except in the light of evolution"
-Theodosius Dobzhansky

You're falling into the trap of homologous and analogous structures. Just because echidnas have spines, doesn't mean they evolved from porcupines. Similarly, just because dolphins have dorsal fins, doesn't mean they evolved from Tuna.
Some humans have genetic anomalies that cause their feet or hands to be webbed. That demonstrates that our genome has the capacity to cause that to happen, but not necessarily that we at one time had an ancestor with webbed feet and or hands.
I don't want to discourage you from scientific inquiry, but perhaps next time you have a hypothesis, you can do a little research before posting.

That's still a pretty big mystery. The fossil record doesn't really have much information on that point. In fact, the evolution of flight as a whole is still quite a mystery.
There are different hypotheses:

1. They were arboreal gliders that evolved powered flight
2. They were terrestrial and used a patagium for intimidation and escape.
3. They evolved independently from a flying proto-mammal

we really don't know though. So if you're looking for something to dedicate your life's research to, there you go!

Hey AustusAleator I did not put on this topic before any research did you know evolutionary studies says that bats are more related to humans than to rodents.
For your question Beetle Bats are supposed to be divide from genus purgatorios which lived about 65 million years ago this is the genus from which even humans evolved but a very long after the evolution of bats.Bats were considered to be close relatives of flying lemurs but genetical studies deny this fact it is said bats and flying lemurs must have evolved from the same ancestor.If you want to know more I might help you.Little epauletted bat does have a face like a flying lemur or even a rat.

Bats have incredibly diverse pheonotypes and karyotypes. There are bats with faces very similar to canids (flying fox) and those with faces more resembling mice (vespertilionids). The shape and appearance of their face is mostly just convergence. A detailed study of their skulls will reveal many differences.
Interestingly, most bats have the same teeth as insectivores (shrews, voles, moles, etc).

David I'd like to see some documentation on the relationship between lemurs and bats. Could you post that? There is a very large taxonomic gap between bats and lemurs (Chiroptera and Primate). I get the feeling that people may say their related just because of the convergent petagium, so could you please post a link to your source?

What did the parasitic Candiru fish say when it finally found a host? - - "Urethra!!"

Astus the flying lemur is not a lemur it has its seperate order Dermoptera."Colugo" is the original Malaysian word for the animal. Although it is also called a "Malayan flying lemur," it is not a lemur and it does not fly - but it is found in Malaysia.It merely glides on the wind currents rather than flying like a bat or a bird. The shocking fact is that it is also found in Rwanda and Burundi in Africa but no web page that I saw says it lives in Rwanda and Burundi.I got this information from the Encarta.There are two species that are extinct and two which are living[I have no idea if the one found in Africa are of a different species] in South East Asia.Bats evolved from the genus purgatorios and lemurs also evolved from this genus but a much later stage all primates have evolved from this genus but I think Tarsiers were the first primates to evolve.The reason why we see so mant differences between bats and primates is because bats evolved about 65 million years but primates evolved in a later stage.And another interesting fact the first primates evolved were nocturnal creatures with large eyes it was only in a later stage primates evolved into a diurnal creatures.Imagine humans having huge eyes and are nocturnal. .I will get you more information Astus if you give me a little more time.The picture in your screen is a flying lemur.